c - 错误C2371，重新定义；不同的基本类型

Question

我收到函数的错误代码 c2371；分开的，最长的和最短的。我认为这与输入参数有关。

error C2371: 'seperate' : redefinition; different basic types
error C2371: 'shortest' : redefinition; different basic types
error C2371: 'longest' : redefinition; different basic types

代码:

#include <stdio.h>

int main(void)
{
  char msg[41];
  int selector = 0;

  printf("Alinur Caglayan - 18050127622 - Lab Work 5 ");
  printf("Please enter a string message with maximum of 40 characters: ");
  gets(msg);

  printf("Please select one of the following functions:\n1) Longest Word Function");
  printf("\n2) Shortest Word Function\n3) Separate Words Function\n4) Exit: ");
  scanf("%d", &selector);

  if(selector == 1)
  {
    longest(msg);
  }
  else if(selector == 2)
  {
    shortest();
  }
  else if(selector == 3)
  {
    seperate();
  }
  else if(selector == 4)
  {
    return 0;
  }
  else
  {
    printf("\nPlease enter a valid integer!\n");
    scanf("%d", selector);
  }
}

char longest(msg)
{
  char *temp = msg, *word = msg, *max = msg;
  int increment = 0, incrementmax = 0;

  do {
    if(!(*temp & ~32)) 
    {
      if(increment > incrementmax) 
      {
        incrementmax = increment;
        max = word;
      }
      increment = 0;
    } 
    else if(!increment++) 
    {
      word = temp;
    }
  } 
  while(*temp++ != 0);

  for(temp = max; (*temp & ~32); ) 
  {
    printf("%c", *temp++);
  }
}

char shortest(msg)
{
  char *temp = msg, *word = msg, *max = msg;
  int increment = 0, incrementmax = 0;

  do {

    if(!(*temp & ~32)) 
    {

      if(increment > incrementmax) 
      {
        incrementmax = increment;
        max = word;
      }
      increment = 0;
    } 
    else if(!increment++)
    {
      word = temp; 
    }
  } 
  while(*temp++ != 0);

  for(temp = max; (*temp & ~32); ) 
  {
    printf("%c", *temp++);
  }
}

char seperate(msg)
{

  char *temp = msg;
  int i;

  printf("Alinur Caglayan - 18050127622 - Lab Work 5 ");
  printf("Please enter a string message with maximum of 40 characters: ");
  gets(msg);

  for(i=0; i < 41; i++)
  {
    if(*temp & ~32)
    {
      printf("\n");
    }
    else
    {
      printf("%c", temp);
    }
    system("pause");
  }
}

Answer 1

有很多错误。

您应该在 main 之前声明您的函数，如下所示:

char shortest(char msg[41]);
char longest(char msg[41]);

或者如果您不想声明它们，您可以在 main 之前定义它们...

你还有一个:

scanf("%d", selector);

虽然应该是:

scanf("%d", &selector);

所有的函数也应该返回一个字符。

已编辑:另一件事是您定义的函数如下:

char longest(msg) {
    ...
}

但是您必须指定参数的类型，如下所示。

char longest(char msg[41]) {
    ...
}